First, you need to make sure that the person with the recipient role is set up and their email address is correct. It is also necessary to check that the recipient is there in the context.
If all of the above is correct, you have the customization available by accessing the notification configuration section as an administrator, where you will find a specific section for this parameterization.
To access follow the following steps:
1. Access Notifications from the menu
2. Go to the Settings tab
3. Whitelist @globaleaks.org on your site and try again. An example configuration can be seen below
For more information, you can access the Alerts Channel website.